196 ■ PON GO 



length of lower molar series, 72. Ex specimen from Landak, Selenka 

 Collection, No. 1, Munich Museum. 



Among the skulls of the Ourang from Landak brought by Mr. 

 Selenka, most of which are those of young animals, are two of old 

 adult males, and these are entirely different in appearance, quite suffi- 

 ciently so, if they belonged to a genus not known to vary so widely 

 in cranial characters, to constitute them distinct species. No. 1, whose 

 measurements are given above is in some degree the smaller of the 

 two, with but a slightly sloping facial region, a braincase considerably 

 elevated above the orbits, and with a low bony crest from the posterior 

 part of the frontal to the occiput. The rostrum is but moderately 

 long, and the orbits are round and not very close together. The face 

 is quite broad for its length, and the ridges, rising from the outer side 

 of the orbits, form an inverted V on the frontal. The other No. 6, is 

 a long, comparatively narrow skull, with a very sloping facial region, 

 and a rather long rostrum. The braincase is rounded, rather broad 

 across the parietals, and less raised above the orbital ridges than that 

 of No. 1, and instead of a crest, the two low ridges, from the outer 

 side of the orbits, run backward on top of the skull, drawing nearer 

 together as they go to the occiput. The orbits are very large, oblong 

 in shape, and quite near together. It will thus be seen how absolutely 

 different these two skulls are, and yet they do not exhibit any greater 

 variation than can easily be found among the crania, not only of all 

 forms of Ourangs, but also of the Chimpanzees and Gorillas. 



The following dimensions are from a skull of the Batangtu Dis- 

 trict, Borneo : 



Measurements. Adult Male No. 141, from Batangtu Region, 

 (Selenka Coll.). Total length, 239; occipito-nasal length, 171; inter- 

 temporal width, 74; breadth of braincase, 105 ; Hensel, 172; zygomatic 

 width, 174 ; extreme width of orbits, 124 ; width of rostrum at canines, 

 73; palatal length, 85.2; length of upper canines, ii; length of upper 

 molar series, 61.7; length of mandible, 167; length of lower molar 

 series, 70.2. 



This is a large massive skull a little longer than high, with a fairly 

 wide braincase but without much depth. There is no long crest, but 

 two ridges start from the outer side of the orbits and extend back- 

 ward in parallel lines on top of the skull, turning outward at the inter- 

 parietal, and join the lateral expansion of the occipital region. The 

 orbits are large, higher than wide, separated by a bony septum 

 16.9 mm. broad. The rostrum protrudes considerably beyond the line 



